P1129 - Downstream Oxygen Sensors Swapped from Bank to Bank
- Manifold Absolute Pressure Sensor harness is open or shorted
- Manifold Absolute Pressure Sensor circuit poor electrical connection
- Engine hard to start
- Rough or erratic idle speed
The Manifold Αbsolute Pressure (MΑP) sensor generates a signal that is proportional to the amount of vacuum in the intake manifold. The signal is sent to the Engine Control Mudule (ECM) and the information is used to control the air/fuel mixture ratio. Faulty MΑP sensor can cuase the engine to stall, surge or a rough idle.